This invention relates generally to carburetors for internal combustion engines and, more particularly to a fuel vapor generator capable of being incorporated within such carburetors for increasing the efficiency thereof.
The carburetor is a proportioning fuel-air mixing device which can be found in most internal combustion engines. Generally, carburetors include a Venturi tube, more commonly referred to as the choke tube in which the fuel is mixed with a proper proportion of air. Within the Venturi tube of the carburetor air passes through the tube during engine operation while means are connected to the tube for supplying a fine mist of tiny droplets of fuel, such as gasoline, through and into the air stream. With such an arrangement, the droplets of gasoline moving rapidly into the combustion chamber or cylinders of an engine do not ordinarily become completely vaporized even though passed over a heated plate. As a result, somewhat inefficient combustion is obtained because the fuel does not burn completely and some of the unconsumed droplets exit from the engine exhaust as a misty waste. This incomplete fuel evaporation causes poor air to fuel mixing, causing an incomplete combustion to take place with the resultant effect of poor fuel energy efficiency. In addition, a contaminating or polluting stream of gaseous material leaves the engine, thereby constituting a primary cause of the contamination of the atmosphere in regions of high automotive traffic concentration, such as major cities.
There have been many attempts in the prior art to overcome this problem of incomplete combustion. Examples of two such attempts can be found in U.S. Pat. Nos. No. 3,278,174 and 3,325,152 both issued to G. I. Wahnish. In the above-mentioned U.S. Patents, an attempt was made to completely vaporize the incoming fuel prior to entering the Venturi or choke tube. Unfortunately, the type of arrangements described in the above-mentioned patents, although providing for better fuel to air mixing ratio than in the past, still have drawbacks associated therewith For example, the type of arrangement set forth in U.S. Pat. No. 3,278,174 provides for an atomization device which also has a portion thereof directly incorporated within the Venturi tube and which includes a vaporization mechanism which still renders less than total fuel vaporization outside the Venturi tube. With respect to U.S. Pat. No. 3,325,152, this patent introduces a secondary stream of air into the vaporization chamber and consequently may lead to safety problems.
It is therefore generally recognized in the field that it would be highly desirable to improve upon the efficiency of the carburetor of an internal combustion engine by providing totally vaporized fuel into the Venturi or choke tube thereof.